1. Field of the Invention
The present invention relates to a liquid developer.
2. Description of the Related Art
A powdery developer (what is called toner) has conventionally been employed as a developer used in an image formation apparatus of an electrophotography type. With the powdery developer, even when a content of a coloring agent is not higher than 10 mass % with respect to 100 mass % of a resin because of increase in particle size (such as 5 μm or greater) from a point of view of prevention of scattering or the like, an image of high density can be obtained.
On the other hand, with a liquid developer, since toner particles are dispersed in an insulating liquid, the toner particles can be prevented from scattering in atmosphere even when a particle size of the toner particles is made smaller. Thus, since a liquid developer can have a smaller particle size of the toner particles, a high-quality image is obtained. When a particle size of the toner particles is made smaller, however, a high-density image is less likely to be obtained and hence a content of the coloring agent should be increased. When the content of the coloring agent is increased, viscoelasticity of a resin contained in the toner particles becomes higher (a filler effect), which may cause deterioration in fixability of the toner particles and resultant lowering in glossiness of an image.
For example, Japanese Laid-Open Patent Publication No. 2002-202645 describes a method for improving glossiness of an image. This publication describes a method for improving fixability without impairing uniformity of an image by forming a water-clear toner layer on a color toner image once formed, and describes increase in gloss of an image with an amount of attached transparent toner.
Japanese Laid-Open Patent Publication No. 10-207130 describes a method for providing a surface of an image with gloss. This publication describes a method for coating an output image surface by applying a solution mainly composed of an organopolysiloxane copolymer obtained by grafting a vinyl-based compound or a copolymer obtained by making blocks of organopolysiloxane from a vinyl-based compound to the image surface and drying the same.